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    <meta charset="UTF-8">
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    <title>Document</title>
    <script type="text/javascript" src="js/jquery-3.5.1.js"></script>
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<body>
<div>前后端交互</div>
<script type="text/javascript">
    /*
        前后端交互-异步编程与promise概述
     */
    // console.log(typeof Promise);
    // console.dir(Promise)
    var p = new Promise(function (resolve, reject) {
        // 这里用来实现异步任务
        setTimeout(function () {
            var flag = true;
            if (flag) {
                //正常情况
                resolve('hello');
            }else{
                //异常情况
                reject('出错了');
            }
        }, 100)
    });
    p.then(function (data) {
        console.log(data)
    },function (info) {
        console.log(info)
    })
</script>
</body>
</html>